灌溉模式对苹果树光合特性及叶绿素荧光参数的影响OA

[Objective]The response mechanism of photosynthetic characteristics and chlorophyll fluo-rescence parameters of three apple tree cultivars to the two irrigation modes was compared to provide a theoretical basis for selecting the suitable irrigation mode for dwarfing cultivation of the three cultivars in Aksu.[Method]Five-year-old apple trees of Yanfu No.6,Wanglin and Venus Gold were selected as re-search subjects.Two irrigation modes,one row one tube(W1)and one row two tubes(W2),were set up.The combined characteristics and chlorophyll fluorescence parameters of 3 varieties of apple trees under different irrigation modes were determined from 10:00 am to 20:00 am on May 20(immature fruit stage)and July 20(fruit expansion stage).[Result]Under the two irrigation modes,the daily variation trends of Pn,Tr and Gs in the leaves of the three cultivars in the immature fruit stage and fruit expansion stage were basically the same,showing an overall pattern of"M"shape.The first and second peaks appeared at 12:00 and 16:00,respectively,and the first peak was higher than the second one.The diurnal variations of Fo,Fv'/Fm'and ETR values of the leaves increased first and then decreased,while the diurnal variations of Ci,Fm,Fv/Fo and Fv/Fm values decreased first and then increased.Under the W2 irrigation mode,the Pn,Tr,Gs,Fo,Fv'/Fm'and ETR values of Yanfu No.6 and Venus Gold in both two growth stages were the lar-gest.The leaf Pn,Tr,Fo,Fv'/Fm'and ETR values of Yanfu No.6 in immature fruit stage were increased by 24.3%,0.5%,9.8%,3.8%and 4.1%,respectively,compared with those under W1 irrigation mode.In the expanding stage,they were increased by 33.3%,19.2%,8.8%,8.9%and 4.1%,respectively,com-pared with those under W1 irrigation mode.The leaf Pn,Tr,Gs,Fo,Fv'/Fm'and ETR values of Venus Golden in immature fruit stage were increased by 41.5%,11.2%,34.2%,1.7%,9.8%and 31.5%,respec-tively,compared with those under W1 irrigation mode.And in the fruit expansion stage,they were in-creased by 6.2%,20.4%,31.9%,8.2%,11.2%and 38.6%,respectively,compared to those under W1 irrigation mode.The Fv/Fo values of Yanfu No.6 and Wanglin fruits in the expanding stage were increased by 2.1%and 24.6%compared with those under W1 irrigation mode,respectively.[Conclusion]Yanfu No.6 and Venus Gold showed stronger photosynthetic capacity and better adaptability to light environment under one row two tubes(W2)irrigation mode,while Wanglin apple showed better photosynthetic characte-ristics and chlorophyll fluorescence parameter under one row one tube(W1)irrigation mode.